1. Field
This application concerns a device for quickly stopping a medical or dental drilling tool, also referred to as a “quick stop” device.
2. Description of Prior Art
Such a class of device is disclosed, for example, in the patent application DE 10 2008 032 704 A1. The device comprises a drilling tool with two concentric parts which are axially slidable against each other, wherein the inner part is pre-stressed against the outer part axially in the drilling direction by means of a spring and, if there is no counteracting force or such is insufficient, slightly projects with its tip over the tip of the outer part in the drilling direction. Furthermore, a device is provided that interrupts the drive of the drilling tool when the inner part is shifted axially in relation to the outer part, wherein the device is connected to an electromagnetic sensor that detects the axial sliding of the inner part against the outer part.
The sensor is designed as an end position sensor that is located on the rear end of the drilling tool (the end connected to a drive) and detects any movement of the broadened end of the inner part, which protrudes from the outer part of the drilling tool. However, this structure is of considerable disadvantage when the quick stop device is supposed to be integrated into a handpiece head, particularly a contra-angle handpiece head, since, particularly due to the constricted space in the handpiece head there is hardly any room for the sensor and for the displacement of the broadened end of the inner part. Moreover, the end position sensor hinders the drilling tool from being connected to a fluid supply.